$profile = '<p>イリノイ州シカゴにて、アイルランド系の家庭に、9</p>';
$dom = new DOMDocument();

// This version preserves the original characters
$contentType = '<meta http-equiv="Content-Type" content="text/html; charset=utf-8">';
$dom->loadHTML($contentType . $profile);
echo $dom->saveHTML();

// This version will HTML-encode high-ASCII bytes
$dom->loadHTML('<meta charset="utf8">' . $profile);
echo $dom->saveHTML();

// This version will also HTML-encode high-ASCII bytes,
// and won't work for LIBXML_DOTTED_VERSION >= 2.12.0
$dom->loadHTML('<?xml encoding="utf-8" ?>' . $profile);
echo $dom->saveHTML();